The basic design of barbells and dumbbells and other free weight weightlifting devices are well known and appreciated. Typically, a handle or bar is inserted through a central opening within one or more weight plates. An inside collar is usually secured or fixed to the handle or bar inboard the one or more weight plates on each end of the bar or handle. About the outboard side of the one or more weights, there is usually provided another collar that is secured to the handle or bar. Thus, about each end of the handle or bar there is secured one or more weight plates between two spaced apart collars. 
Safety is of paramount concern in securing weight plates to a handle or bar. It is, of course, important to retain the weight plates on the bar or handle, and it is also desirable that the weight plates not be able to freely rotate or turn on the handle or the bar. Simply put, weight plates can be extremely heavy and if they inadvertently fall from a bar or handle, it is certainly possible that an injury may result. 
In addition, the securing mechanisms traditionally used to secure weight plates to handles and bars do very little to enhance the overall appearance of such weight lifting devices. This is because the securing mechanisms typically lie outside of the weight plates themselves, and, as pointed out above, sometimes these securing mechanisms are separate components from the weight plate and the supporting handle or bar. In the end, securing mechanisms of the prior art  are not always totally reliable and even the more reliable ones do very little to enhance the overall appearance and design of the weight lifting device. 
Therefore, there has been and continues to be a need for a weight lifting device such as a barbell or a dumbbell, that is designed such that the weight plates are securely held on the handle or bar and that the actual securing mechanism is inconspicuous as practically possible in order to yield a reliable and aesthetic pleasing product. 